Mark Sanchez chugged around the perimeter of the New Meadowlands Stadium turf today, pumping his fist as some 12,000 fans roared.

It was actually a penalty lap for the Jets quarterback, who had just been flagged for a false start during the team’s final mini-camp practice. But it felt more like a victory lap.

“I’ve never been cheered for when I made a mistake like that,” Sanchez said.

Four months after having surgery to strengthen the patella-stabilizing ligament in his left knee, the team’s franchise quarterback completed mini-camp ahead of where he expected, both physically and mentally.

He admitted he had questions about how his knee would fare in its biggest test so far. But doing team drills in three practices this week — the team’s plan had been to hold him out of the two afternoon sessions — was an affirmation of not only his physical recovery, but the mental progress he made in the meantime.

“It might have been the best thing for me,” Sanchez said. “It’s hard to see that when I’m in a cast and can’t do anything, and I wanted to be working out, but mentally that might have been the best grind of football I’ve ever had.”

Sanchez’s knee rehab progressed ahead of schedule this spring, as he eased his way back into running, football-related activities and finally practice. He praised “reactive rehab,” in which he simulated his throwing motion in the training room while using dumbbells, resistance cords and weight vests. He also managed to add muscle in his lower body.

But as the team remained cautious with him, he knew to stay on track with his goals for his second season, he had to be a champion in the classroom.

Sanchez adopted a “you name it, I’m trying to master it” approach. He became a de facto assistant coach, working alongside offensive coordinator Brian Schottenheimer and quarterbacks coach Matt Cavanaugh.

Head coach Rex Ryan cited Sanchez putting in six hours at the facility on a Saturday afternoon and returning again on Sunday.

“No player that I’ve ever been around worked as hard as Sanchez did in the offseason,” Ryan said. “No player.

“Yeah, I had Ray Lewis and all that. But the mental preparation and everything else this young man had to do day in and day out, and what he signed up to do — he’s exceeded everybody that I’ve ever been around.”

Sanchez’s goal had been to “attack” this mini-camp. He said it was both “enlightening” and “inspiring” to see how quickly he absorbed knowledge this offseason, on everything from protections to footwork to hand placement. What’s next?

He’ll host the team’s other quarterbacks and receivers in California for an extra week of work in late July. He’ll study mini-camp film with the objective to be “perfect” for training camp. He’ll seek out fellow USC Trojan Carson Palmer for advice on year two in the NFL. He’ll also try to sneak in a vacation and a few charity events to recharge for the season.

He said he doesn’t feel like he needs to be in catch-up mode for the next six weeks, because he said the last two weeks “really brought me back to speed.”